As a graduate student, roboticist Robert Wood became fascinated with the idea of developing a life-size, flying bee machine. Able to soar above trees or maneuver around obstacles, such a robot, Wood figured, could gather secret information for military missions or monitor hazardous environments without risking human lives.

Later, when he set up his own lab at Harvard University, Wood developed a system to cut materials into well-defined shapes and fold them into insect-sized parts. Creases ...